Allow specifying querysets.

Given the number of kwargs that some constructors take, perhaps the
better thing would be to be able to say "this field gets these
kwargs", so we could instead pass something like
other = { 'foo': {'queryset': Foo.objects.all()}, 'bar': {'fwip': 'baz'} }.
 - Legacy-Id: 147

ietf/contrib/form_decorator.py

@@ -1,7 +1,7 @@
 ## formfield_callback generator
 ## http://www.djangosnippets.org/snippets/59/
 def form_decorator(fields = {}, attrs = {}, widgets = {}, 
-    labels = {}, choices = {}):
+    labels = {}, choices = {}, querysets = {}):
     
     """
     This function helps to add overrides when creating forms from models/instances.
@@ -65,6 +65,10 @@ def form_decorator(fields = {}, attrs = {}, widgets = {},
             if callable(choice_set) : choice_set = choice_set()
             kw["choices"] = choice_set
 
+        if f.name in querysets:
+        
+            kw["queryset"] = querysets[f.name]
+            
                 
         return f.formfield(**kw)